1. Field of the Invention
The present invention relates to a method for producing optically active 1-alkoxycarbonyl-2-hydroxymethylcyclopropane-1-carboxylic acids, which are intermediates useful in synthesizing, for example, non-natural amino acids and anti-viral agents.
2. Description of the Background
It has been known that the optically active 3-oxa-2-oxobicyclo3. 1.0!hexane-1-carboxylic acid ester represented by the following general formula (I) is a starting material useful for producing a variety of non-natural amino acids and anti-viral agents (see Helvetica Chimica Acta Vol. 72, 1301-1310 (1989) and Japanese Laid-Open Patent No. 5-78357). ##STR1## In formula (I), R represents an alkyl group having 1 to 10 carbon atoms, which may or may not be substituted with an aryl group, and * designates an asymmetric carbon.
Ester (I) may be produced readily by reacting an optically active epichicrohydrin with a malonate diester. Additionally, a production method from optically active glycidol triflate and malonate diester is known (J. Org. Chem., Vol. 58, 3767-3768 (1993)). However, the optically active epichlorohydrin and glycidol triflate used in these methods are so extremely expensive that such methods are not suitable for industrial production.
A method for producing an optical active substance through the action of esterase on the racemic material, which can be produced inexpensively, to thereby selectively hydrolyze the racemic substance, has been reported (Synthetic Commun., Vol. 21, 1429-1432 (1991). However, this procedure is so complex that the method cannot be considered industrially satisfactory.